[c++] What's this error? - Tilted Forum Project Discussion Community

j0hnb · 11-09-2004, 07:52 AM

What does this error mean?

Undefined first referenced
symbol in file
operator<<(std::basic_ostream<char, std::char_traits<char> >&, Diamond&)/var/tmp//ccR39vYu.o
ld: fatal: Symbol referencing errors. No output written to a.out
collect2: ld returned 1 exit status

I'm trying to overload the << operator within a class, and this is the only part that I can't seem to get working. Let me know if you need more code or if you know what I should check out to fix it. Thanks

MXL · 11-09-2004, 05:34 PM

Show the the code in question.

n0nsensical · 11-09-2004, 11:17 PM

It's a linker error meaning operator<< with those parameters is not defined. Remember that if you're trying to do something like
Class c;
cout << c;
the operator<< function must either be a member of ostream or a global function. If you make it a member of Class it's not going to work the way you expect.

Rekna · 11-10-2004, 08:18 AM

What nonsensical is basically saying is put it as a global function in your header file (not part of the class) and then make that function a friend of your class to get private access.

11-09-2004, 07:52 AM	#1 (permalink)
j0hnb Crazy Location: Arnold, MD	[c++] What's this error? What does this error mean? Undefined first referenced symbol in file operator<<(std::basic_ostream<char, std::char_traits<char> >&, Diamond&)/var/tmp//ccR39vYu.o ld: fatal: Symbol referencing errors. No output written to a.out collect2: ld returned 1 exit status I'm trying to overload the << operator within a class, and this is the only part that I can't seem to get working. Let me know if you need more code or if you know what I should check out to fix it. Thanks

11-09-2004, 05:34 PM	#2 (permalink)
MXL Tilted Location: Maryland	Show the the code in question.

11-09-2004, 11:17 PM	#3 (permalink)
n0nsensical Junkie Location: San Francisco	It's a linker error meaning operator<< with those parameters is not defined. Remember that if you're trying to do something like Class c; cout << c; the operator<< function must either be a member of ostream or a global function. If you make it a member of Class it's not going to work the way you expect.

11-10-2004, 08:18 AM	#4 (permalink)
Rekna Junkie	What nonsensical is basically saying is put it as a global function in your header file (not part of the class) and then make that function a friend of your class to get private access.